Log grapple with gripper means



March 5, 1968 R. H. HUNGER 3,371,952

LOG GRAPPLE WITH GRIPPER MEANS Filed Oct. 24, 1965 2 Sheets-Sheet 1ENTOR. R/ CHA/YD 17. 6 04/4192 March 5, 1968 R. H. HUNGER 3,

LOG GRAPPLE WITH GRIPPER MEANS 2 Sheets-Sheet 2 Filed Oct. 24, 1965 Fl5. 5 I l INVENTOR. leis/1 4220 6 04/6192 14 77a avers United StatesPatent 3,371,952 LOG GRAPPLE WliTl-I GRIPPER MEANS Richard H. Hunger,Ashland, Wis, assignor to Beloit Con poration, Beloit, Wis. acorporation oi Wisconsin Filed Oct. 24, M65, Ser. No. 504,53 lllClaims". (Cl. 294-438) ABSTRACT OF THE DTSQLOfiURE Log grapplingapparatus having a pair of coopertaing jaws pivotally connected to asupporting head, and hy-- This invention relates to log handlingapparatus and more particularly to a log grapple having improvedstructure for engaging and holding bunched logs.

Pulpwood or other log grapples ordinarily consist of a pair ofhydraulically actuated jaws which can be brought into grasping relationto a bunch of logs. Occasionally, when the bunch is either too large ortoo small, the disposition of the logs within the jaws will be unstableand the logs will slip and even fall out of the grapple under someconditions. The operator must therefore be careful in operating thegrapple to make sure that the bunches of logs are within the capacity ofhis equipment. If the hunch is too large, he must take only part of it,or if it is too small, he is obliged to have more logs moved onto thepile before they can be adequately handled.

It is an object of this invention to increase the handling capacity of alog grapple in the sense that greater variation is obtained in the sizeof the bunches of logs which can be handled. Stated somewhatdifferently, it is an object of this invention to provide a log grapplewhich is capable of handling different size bunches of logs with equalfacility.

Another object of the invention is to provide a grapple structure forholding logs in a more positive manner than prior art grapples, so thatthe logs are clamped firmly in the grapple.

Still another object of the invention is to provide a hydraulicallyactuated log grapple structure for firmly holding a bunch of logs inwhich the gripping elements are sequentially operated to insure that thedesired number of legs will be grasped by the device in a stablearrangement.

Briefly described, the invention resides in adding to generallyconventional grapple structure an auxiliary gripping means which isoriented to move parallel to the general plane of the grapple jaws,eflectively to vary the gripping area between the jaws of the grapple.Thus, this additional holding means can be moved into engagement withthe logs in the grapple to hold them in place regardless of how full thegrapple is, that is, regardless of how large the bunch of logs happensto be. The auxiliary gripping means is hydraulically actuated and isoperated from the primary jaw closing circuit through a sequence ordelayed-lift valve so that the auxiliary holding means is actuated afterclosure of the primary grapple jaws. This insures that the jaws willhave closed on the bunch of logs, and also balances the forces which areapplied in holding the logs.

ICE

Other objects, advantages and new features of the invention will becomeapparent from the following detailed description when read inconjunction with the accompanying drawings wherein:

FIGURE 1 is a combination view including an elevational view of thegrapple structure in its holding relation to a small bunch of logs and adiagrammatic showing of the hydraulic circuit which is employed for theVarious actuating motors of the grapple;

FIGURE 2 is a side view of the grapple as seen in FIGURE 1, the varioushydraulic lines having been omitted from FIGURE 2 for purposes ofclarity; and

FIGURE 3 is an elevational view of a grapple according to the inventionshowing the grapple in its relation to a larger bunch of logs than wasshown in FIGURE 1.

The log grapple according to the illustrated embodiment of the inventionis generally indicated at 10 throughout the several views of thedrawing. It will be understood by those skilled in the art that thegrapple is intended to be attached to a suitable boom or othermanipulating structure so that it may be moved into position to engageand grapple a bunch of logs. The attachment of the grapple to themanipulating structure is suggested in the drawing by the universaljoint 12 which permits the grapple to assume a vertical orientationregardless of the position of the boom to which the grapple is attached.

The grapple itself consists of a supporting head 14 which is attached tothe universal joint 12. The supporting head 14 is made up of verticalside journal plates 15 and 16 which are held in spaced parallel relationby means of a transverse member 18. Other mounting portions of thesupporting head 14 are the journal plates 20, 22, 24 and 25, which aremounted in spaced parallel relation to the side plates 15 and 16 bymeans of suitable supporting elements such as plates 25 and 28. Themanner in which the various elements are journaled in these plates willbe disclosed below.

Grapple jaws 3t and 32 are mounted on the head 14 for pivotal movementabout the spaced axes defined by shafts 34 and 35, respectively. Thejaws 30 and 32 are shaped in generally conventional manner so that theymay be brought into encircling relation to a bunch of logs to behandled. For operating the jaws 3t) and 32, a pair of double-actinghydraulic motors 36 and 3d are provided. The cylinders of these motorsare pivotally attached to the supporting head 14, as by means of pins 40and 42, and the extensible rams of the cylinders are pivotally connectedto the jaws 30 and 32 by means of pivot shafts 44 and 45, all ingenerally conventional fashion.

The auxiliary gripping means in the illustrated embodiment of theinvention are the two spaced gripper arms 46 and 48 which are pivotallyattached to the supporting head 14 at the right side of the. assembly asseen in FTGURE 1. As shown, the gripper arm 46 is pivotally mountedbetween the plates 15 and 20 by means of a lug 50 attached to thegripper arm and a pivot pin 52 extending between the plates 15 and 2G.The gripper arm 48 is mounted in similar fashionbetween the plates 16and 22 by means of a lug 54 and a pivot pin 56.

As will be apparent from an inspection of FIGURE 2, the gripper arms 46and 43 are of triangular box-frame construction. This arrangementprovides structural rigidity and strength while providing a wedge effectas the apex of the gripper arm cross section is: brought into engagementwith the logs which are held within the grapple. Thus, the gripper arms'46 and. 48 will bite into the logs and hold them in place. Anotheraspect of the shape of the gripper arms is best illustrated in FIG- URES1 and 3, where it will be seen that the arm 46 has a generallyvertically extending portion 62 and two angled portions 64 and 65 whichtogether extend substantially transversely of the grapple jaws. Thearrangement is such that the force exerted on the logs by the gripperarms is toward the opening ends of the jaws and generally aligned withthe center line between the jaws regardless of the number of logs in thebunch. Thus, when the logs lie within the jaws in such a manner that arelatively short travel of the gripper arms is required to engage thelogs, the surface of the portion 64 of gripper arm 46 and thecorresponding portion of gripper arm 48 will engage the logs to impart aforce generally in the direction of the arrow 66. On the other hand,where, as in FIGURE 3, the gripper arms must travel through a greaterare to come into contact with the logs, the surface of the portion 65and the corresponding portion of gripper arm 48 will engage the logs toimpart a force generally in the direction of the arrow 68, againdirected predominantly along the center line between the jaws.

For moving the gripper arms, hydraulic motors and 72 are provided. Themotor 70 is anchored between the plates 15 and 24 by means of a pivotpin 74, the opposite end of the motor being connected to a suitable lug75 on the gripper arm 46 by means of a pivot pin 76. It will beunderstood that the motor 72 is similarly connected on the opposite sideof the supporting head 14.

In the hydraulic circuit of the present invention, as illustrated inFIGURE 1, hydraulic fluid is supplied to the various motors from areservoir 78 by means of a suitable pump 80. Opening and closing of thegrapple is under the control of a spool valve 82, which, in the positionshown, supplies hydraulic fluid to the grapple closing ports 84 and 85of the motors 36 and 38, respectively, over the line 86 through theT-connection 88 and then over the lines 90 and 92. As the rams areextended to close the jaws 3i and 32, fluid is returned to the reservoirfrom the retracting ports 94 and 95 of the motors 36 and 38 over lines96 and 98 to the T-connection 106 and then over the line 1'02 to valve82, and then over the line 104 to the reservoir. To open the jaws, thespool of the valve 82 is shifted so that the pressure side of the pump80 is connected to the line 102 rather than to the line 86, that is, thepres sure and return relationship of these two lines are reversed.

It is desirable to close or actuate the gripper arms 46 and 48 after thegrapple jaws have closed, so that the logs will not be forced out of thegrapple by the operation of the gripper arm. For this purpose, theextending ports 105 of the motor 70 is connected to the line 86 over aline 196 and through a delayed-lift or sequence valve 108 ofconventional construction. It will be understood by those skilled in theart that the valve 198 permits fluid to enter the line 106 only afterthe pressure in the line 86 reaches a predetermined level. Thus, as thejaws 30 and 32 close, the pressure in the closing circuit will build upand when it reaches a predetermined value, fluid will be admitted to theline 196 to extend the motor 70 to cause the gri per arms 46 and 48 tocome into forcible engagement with the logs. This sequential operationis not required in the opening action of the grapple, so that theretracting port 110 is simply connected to the return line 102 over aline 112 and a T -connection 114.

The operation of the grapple should be readily apparent from the abovedescription. The following summary, however, should be of some aid inthe understanding of the present invention. It will be understood thatthe boom structure is first manipulated to bring the grapple intoposition to pick up a bunch of logs. The valve 82 is then actuated toopen the jaws to their wide open condition. The boom is then actuated tolower the grapple into straddling relation to the logs which are desiredto be handled.

Upon lowering of the grapple, the valve 82 is changed to connect theclosing side of the hydraulic circuit to the motors to close the jaws3t) and 32. As the jaws engage the logs, the resistance presented by thelogs will cause the pressure to increase in the line 86 to the pointwhere the delayed-lift valve 193 will permit fluid to enter the line166. At this time, the gripper arms will be extended to engage the logsand to add their holding action to that of the grapple arms.

If the configuration of the bunch of logs is such as to ermit only ashort travel of the gripper arms, as in the case shown in FIGURE 1, theportion 6-4 of the gripper arm 46, for example, will engage the logs ashas been described above. If, on the other hand, the configuration ofthe logs is relatively less in the vertical direction so that thegripper arms must travel further around their respective pivot pins inorder to engage the logs, then the next angled section 65 will come intocontact with the logs. In this manner, the forces exerted on the logswill always be predominantly directed along the center line between thegrapple jaws.

Release of the logs is accomplished by moving the valve 82 to its otherposition, thus supplying hydraulic fiuid to the retracting ports of thevarious motors to open the grapple jaws 3t? and 32 and to withdraw thegripper arms from their operative position against the logs.

It should now be apparent that a grapple has been described which fullymeets all of the objects of the invention set forth above. Inparticular, the bunches of logs are held rigidly and without danger ofslipping out of the jaws regardless of the degree of fullness of thegrapple. The operator is thus relieved of the necessity of watching tosee that just the right number of logs is involved in the bunch that heis intending to handle and the overall efficiency of the handlingoperation is improved. The shape of the auxiliary gripping arms is suchthat the gripping action is maintained in the proper direction at alltimes and the sequencing action of the hydraulic circuit insures thatthe grapple jaws are closed before the auxiliary gripping means isactuated.

It will, of course, be understood that various changes may be made inthe form, details, arrangements and pro portions of the parts withoutdeparting from the scope of my invention as set forth in the appendedclaims.

I claim:

ll. Log handling apparatus comprising a log grapple having a supportinghead, a pair of cooperating grapple jaws movable between a spread apartposition and a log grappling position, each of said jaws having anopening end portion and an opposite end portion, means for pivotallymounting said opposite end portion on said supporting head to permit thejaws moving between said positions, power means for moving said jawstoward each other to hold a bunch of logs therebetween, auxiliarygripping means mounted on said supporting head for movement relativethereto and having a portion thereof extending generally transversely ofsaid jaws, and power means for moving said auxiliary gripping means intoforcible contact with said logs to hold them firmly in said jaws.

2. Log handling apparatus as recited in claim 1, said auxiliary grippingmeans being arranged to move in a direction toward the opening ends ofsaid jaws in the grapple position, effectively to reduce the grippingarea between said jaws.

3. Log handling apparatus as defined in claim 1, said auxilary grippingmeans comprising a gripper arm pivotally mounted on said supporting headfor movement parallel to the general plane of movement of said jaws.

4. Log handling apparatus comprising a log grapple having a supportinghead, a pair of grapple jaws pivotally mounted on said supporting head,power means for moving said jaws toward each other to hold a bunch oflogs therebetween, auxiliary gripping means mounted on said supportinghead and having a portion thereof extending generally transversely ofsaid jaws, said auxiliary gripping means comprising a gripper armpivotally mounted on said supporting head for movement parallel to thegeneral plane of movement of said jaws, said gripper arm being shapedthat a force is applied to said logs predominantly along the centerlinebetween said jaws regardless of the amount of arcuate travel required tobring said gripper arm into engagement with said logs, and power meansfor moving said auxiliary gripping means into forcible contact with saidlogs to hold them firmly in said jaws.

5. Log handling apparatus as recited in claim 4, said gripper arm havinga first portion thereof extending sub stantially normally to thecenterline between said jaws when said gripper arm is displaced only ashort distance into engagement with said logs and a second portionangled with respect to said first portion so that said second portionwill extend substantially normally to the centerline between said jawswhen a greater arcuate travel of said gripper arm is required to bringsaid gripper arm into engagement with said logs.

6. Log handling apparatus comprising a pair of cooperating grapple jawsmovable between a spread apart first posit-ion and a log grapplingsecond position, each jaw having an opening end portion and an oppositeend portion, auxiliary gripping means movable from a retracted firstposition to a second position for cooperating with the grapple jaws intheir second position to effectively reduce the gripping area betweensaid jaws, first means connected to said jaw opposite end portions andto said gripping means for mounting said jaws for movement between saidjaw positions and mounting said gripping means for movement between itspositions, said first means including a supporting head and means forpivotally connecting said opposite end portions to said head, and saidgripping means including a gripping arms that in a gripping meansretracted position has at least a portion extending generally betweensaid pivot means and the jaw opening end port-ions, and power meansconnected to the first means and the gripping means for moving said jawsfrom their first positions to their second positions and thereafter movethe gripping means to its second position, said power means includingmeans connected to said head and said arm for moving said arm portion ina direction generally toward the jaw opening end portions in the jawsecond position.

7. Log handling apparatus comprising a log grapple having a supportinghead, a pair of cooperating grapple jaws movable between a spread apartfirst position and a log grappling second position, each jaw having anopening end portion and an opposite end portion pivotally connected tosaid head, auxiliary gripping means movable from a retracted firstposition to a second position for cooperating with the jaws in theirsecond position to effectively reduce the gripping area between saidjaws, and power means connected to said jaws and to said gripping meansfor moving said jaws from their first position toward their secondposition and then moving the gripping means to its second position tofirmly hold logs between said jaws.

8. The apparatus of claim 7 further characterized in that the grippingmeans has a portion extending generally between said jaws in their firstposition, and that said power means includes means connected to saidgripping means for moving said gripping means to move said portion in adirection generally toward the jaw opening end portions in the jawsecond position.

9. Log handling apparatus comprising head means, a

pair of cooperating grapple jaws mounted on said head means relativelymovable between a spread apart first position and a log grappling secondposition determined by the number of logs being grappled, each jawhaving an opening end portion and an opposite end portion, auxiliarygripping means mounted on said head means movable from a retracted firstposition to a second position for cooperating with the grapple jaws intheir second position to efifectively reduce the gripping area betweensaid jaws, said grip ing means having a portion extending generallytransversely relative said jaws, first means connected to said jawopposite end portions for mounting said jaws for relative movementbetween said jaw positions, and power means mounted on said head meansconnected to said jaws and gripping means for relatively moving saidjaws from their first position toward their second relative position andsaid gripping means toward its second position, said power meansincluding hydraulic means connected directly to said gripping means formoving the gripping means mechanically independently of said jaws andrelative thereto so as to move said portion generally toward the jawopening end portions in the jaw second position uninfiuenced by thegripping area to be reduced to a position to abut against a log betweensaid jaws in the jaws second relative position irrespective of thenumber of logs determining said second position to apply a force to thelogs predominately along the centerline between the jaws and towardsections of said jaws near their said opening end portions.

10. Log handling apparatus comprising head means, a pair of curvedcooperating grapple jaws movable between a spread apart position firstposition and a log grappling second position, each jaw having an openingend portion and an opposite end portion, said curved jaws forming agripping area having an apex adjacent the opening end portions thereofwhen in said second position, auxiliary gripping means mounted on saidhead means movable from a retracted first position to a second positionin the direction of said apex to effectively reduce the gripping areabetween said jaws, first means connected to said jaw opposite endportions for pivotally mounting said jaws on said head means formovement between said jaw positions, and power means mounted on saidhead means connected to said jaws and gripping means for moving saidjaws from their first position toward their second position and thensaid gripping means toward its second position, said power meansincluding a pair of double-acting hydraulic motors connected to thefirst means for moving the jaws between their positions, one of saidmotors being connected to one of said jaws and the other motor beingconnected to the other jaw.

References Cited UNITED STATES PATENTS 3,119,637 1/1964 Eaves 294-673,252,609 5/1966 Ellis 29488 X 3,262,595 7/1966 Seip 214653 3,295,882 1/1967 Wallberg 294-104 FOREIGN PATENTS: 1,287,488 2/ 1962 France.

GERALD M. FORLENZA, Primary Examiner. G. F. ABRAHAM, Assistant Examiner.

